1. Field of the Invention
This invention relates generally to a hydraulic power steering mechanism for a vehicle, and more particularly to improvements in providing a hydraulic power assistance output to a somewhat lesser extent in case of a higher level vehicle traveling speed than would be the case for a lower level vehicle speed.
2. Description of the Prior Art
While many attempts have been proposed in moderation of behavior of the hydraulic power steering mechanism at the higher level vehicle speed, none have proven to be entirely sufficient due to lacking the intended moderation character when the manual steering wheel operation speed is slowed. The moderation is required for safety purpose, since the general purpose of power assistance is concerned with use of a lower level vehicle traveling speed rather than a higher speed which would result in a tendency towards excessive power assistance due to a natural decrease in steering resistance.